Optical component

ABSTRACT

The optical component according to the present invention includes a fixed member including a through hole, and a wavelength conversion member having at least one part thereof arranged in the through hole, where the fixed member is formed with a cut-in part or a hole part in a direction substantially perpendicular to the longitudinal direction of the through hole.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical component including awavelength conversion member for wavelength converting the light from alight source.

2. Description of the Related Art

Conventionally, a light source is proposed that transmits the light fromthe light source to a disperser via a separator such as an optical fiberto disperse the light into a desired pattern or change the color of thelight (see Japanese Laid-Open Patent Publication No. 2003-515899).

A can package in which the semiconductor laser element is hermeticallysealed is also known. The can package is hermetically sealed by a stemmounted with the semiconductor laser element and a cap having a constantthickness. A glass window for extracting the laser light is formed inthe cap, and the glass is fixed to the inner side of the cap by way ofresin adhesive.

SUMMARY OF THE INVENTION

However, the conventional light source merely has a disperser attachedto the distal end of the separator such as an optical fiber, and thusthe light emitting efficiency may not be satisfactory depending on theattaching method, and more improvement is required to be used as anoptical component capable of being attached to the end part of theoptical fiber.

As for the can package, the glass is fixed with resin adhesive, and thusorganic components are volatilized from the resin adhesive. Such organiccomponents become impurities and attach to the inside of the canpackage, in particular, to the glass and the exit end part of thesemiconductor laser element, thereby lowering the optical output of thelaser light.

It is, therefore, an object of the present invention to provide anoptical component that has a simple configuration and that preventslowering of the optical output.

According to the present invention, such aim is accomplished in thefollowing manner.

The optical component according to the present invention includes afixed member including a through hole; and a wavelength conversionmember having at least one part arranged in the through hole; where thefixed member is formed with a cut-in part or a hole part in a directionsubstantially perpendicular to the longitudinal direction of the throughhole. A configuration that is simple and that prevents lowering inoptical output is thereby achieved.

The wavelength conversion member is preferably fixed to the fixed memberusing a fixing member. Therefore, the wavelength conversion member canbe reliably fixed to the fixed member. Furthermore, hermetic sealing isrealized.

The fixing member is preferably a low melting point glass. Inparticular, the low melting point glass having a softening point atlower than or equal to 650° C. is preferable. Degradation of the opticalcomponent can be thereby suppressed.

The fixing member is preferably filled in the cut-in part or the holepart formed in the fixed member when fixing the wavelength conversionmember to the fixed member using the fixing member. Accordingly, theattachment of the wavelength conversion member to the fixed member isreliably performed with a small amount of fixing member, and thuslowering in optical output due to light absorption by the fixing membercan be suppressed.

In addition to the above configuration, the fixed member may include aprojection or a concave part for fitting the wavelength conversionmember at the through hole side. When the fixed member has a projectionon the through hole side, the wavelength conversion member preferablyhas a concave part that mates with the projection, or when the fixedmember has a concave part on the through hole side, the wavelengthconversion member preferably has a projection that fits into the concavepart. With this configuration, the wavelength conversion member can befixed even more reliably.

Preferably, the fixed member is a tubular body with its inner hole beingcircular in a transverse cross section. Chips and cracks of the fixedmember can be thereby prevented.

The fixed member preferably includes a step at the through hole. Thewavelength conversion member is thereby positioned at the step portionof the fixed member, and thus can always be arranged at a constantposition.

The fixed member preferably has a diameter of at least one part of thethrough hole the same as or greater than a diameter of the wavelengthconversion member. The detachment of the wavelength conversion memberfrom the fixed member is thus less likely to occur.

The wavelength conversion member is preferably fitted in the throughhole of the fixed member. The foreign substances are thus prevented fromentering into the through hole.

The wavelength conversion member is preferably obtained by mixing afluorescent material in glass. Degradation of the wavelength conversionmember can be thereby prevented.

The glass is preferably silicate glass. In particular, silicate glasscontaining one or more types of alkali metal oxide, alkali earth metaloxide, boron oxide, phosphorus oxide, zinc oxide is preferable. Theresistance to weather of the wavelength conversion member therebyenhances, and degradation of the wavelength conversion member can beprevented.

According to the present invention, an optical component that has asimple configuration and that prevents lowering of optical output isachieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a configuration of an optical componentaccording to a first embodiment of the present invention;

FIG. 2 is a view showing a configuration of an optical componentaccording to a second embodiment of the present invention;

FIG. 3 is a view showing a configuration of an optical component of acomparative example in which a fixing member is arranged on the sidesurface of the waveform conversion member;

FIG. 4 is a view showing a configuration of a light emitting deviceequipped with the optical component according to the first embodiment ofthe present invention;

FIG. 5 is a view showing a configuration of another light emittingdevice equipped with the optical component according to the firstembodiment of the present invention;

FIG. 6 is a view showing a light emitting device used in evaluating theoptical component according to a first example of the present invention;and

FIG. 7 is a view showing the effects of the first example of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments according to the present invention will now bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a view showing a configuration of an optical componentaccording to a first embodiment of the present invention.

As shown in FIG. 1, the optical component according to the firstembodiment includes a fixed member 1 and a wavelength conversion member2. The fixed member 1 includes a fit-in part 3-2 in which the wavelengthconversion member 2 is fitted, and a through hole 3-1 that contacts thefit-in part 3-2 with a step 4 in between. The outer shape of the fixedmember 1 may be any shape such as circular, rectangular, and ellipticalas long as it is a tubular body, but is preferably circular. Thetransverse cross sectional shape of an inner hole part of the tubularbody, or the through hole 3-1 and the fit-in part 3-2, may be any shapesuch as circular, rectangular, and elliptical, but is preferablycircular. The wavelength conversion member 2 may be of any shape such ascolumn, quadratic prism, elliptic cylinder, sphere, hemisphere etc., butis preferably a column. The wavelength conversion member 2 is arrangedin the fit-in part 3-2 of the fixed member 1, and is fixed to the fixedmember 1 by filling a cut-in part 5-1 formed at the side surface of thefit-in part 3-2 with the fixing member 5-2. Any number of cut-in parts5-1 may be formed, but is preferably equally arranged at the peripheryof the wavelength conversion member 2.

The fixing method of the fixed member 1 and the wavelength conversionmember 2 is that the wavelength conversion member 2 is fixed to thefixed member 1 by pushing the fixing member (low melting point glass)5-2, which is molded so as to comply with the shape of the cut-in partin advance, onto the cut-in part 5-1 with the wavelength conversionmember 2 arranged in the fit-in part 3-2 of the fixed member 1, andperforming heating in this state to fill the fixing member 5-2 in thecut-in part 5-1.

The material of the fixed member 1 is preferably a material that has ananti-corrosion property and that easily adheres to the low melting pointglass, and stainless material may be used.

According to the first embodiment, the attachment of the wavelengthconversion member 2 to the fixed member 1 is reliably performed with thefixing member 5-2 of a smaller amount than in the attaching method (seeFIG. 3) in which the low melting point glass is arranged on the sidesurface of the wavelength conversion member, and thus the affect of thefixing member 5-2 on properties such as light absorption is small.Therefore, according to the first embodiment, the light that exits fromthe wavelength conversion member 2 is discharged without beingattenuated, thereby improving the light emitting efficiency.

FIG. 2 is a view showing a configuration of an optical componentaccording to a second embodiment of the present invention.

As shown in FIG. 2, the optical component according to the secondembodiment includes a fixed member 1 and a wavelength conversion member2. The fixed member 1 includes a fit-in part 3-2 in which the wavelengthconversion member 2 is fitted, and a through hole 3-1 that contacts thefit-in part 3-2 with a step 4 in between. The outer shape of the fixedmember 1 may be any shape such as circular, rectangular, and ellipticalas long as it is a tubular body, but is preferably circular. Thetransverse cross sectional shape of an inner hole part of the tubularbody, or the through hole 3-1 and the fit-in part 3-2, may be any shapesuch as circular, rectangular, and elliptical, but is preferablycircular. The wavelength conversion member 2 may be of any shape such ascolumn, quadratic prism, elliptic cylinder, sphere, and hemisphere, butis preferably a column. The wavelength conversion member 2 is arrangedin the fit-in part 3-2 of the fixed member 1, and is fixed to the fixedmember 1 by filling a hole part 6-1 formed at the side surface of thefit-in part 3-2 with the fixing member 6-2. Any number of hole parts 6-1may be formed, but is preferably equally arranged at the periphery ofthe wavelength conversion member 2.

The fixing method of the fixed member 1 and the wavelength conversionmember 2 is that the wavelength conversion member 2 is fixed to thefixed member 1 by filling the granulated low melting point glass 6-2serving as the fixing member into the hole part 6-1 with the wavelengthconversion member 2 arranged in the fit-in part 3-2 of the fixed member1, and performing heating in this state.

According to the second embodiment, the attachment of the wavelengthconversion member 2 to the fixed member 1 is reliably performed with asmall amount of fixing member 6-2, and thus the affect of the fixingmember 6-2 on properties such as light absorption is small. Therefore,according to the second embodiment, the light that exits from thewavelength conversion member 2 is discharged without being attenuated,thereby improving the light emitting efficiency.

FIG. 3 is a view showing a configuration of an optical component of acomparative example through an attaching method in which the fixingmember is arranged on the side surface of the wavelength conversionmember.

As shown in FIG. 3, the optical component with the low melting pointglass arranged on the side surface of the wavelength conversion memberincludes a fixed member 1 and a wavelength conversion member 2. Thefixed member 1 includes a fit-in part 3-2 in which the wavelengthconversion member 2 is fitted, and a through hole 3-1 that contacts thefit-in part 3-2 with a step 4 in between, but differs from the opticalcomponents shown in FIGS. 1 and 2 in that a cut-in part nor a hole partis formed at the side surface of the fit-in part 3-2. The fixed member 1is a tubular body having a circular inner hole. The wavelengthconversion member 2 has a columnar shape. The fixing method of the fixedmember 1 and the wavelength conversion member 2 is that the wavelengthconversion member 2 is fixed to the fixed member 1 by inserting the lowmelting point glass 6-3 molded into a ring shape in the wavelengthconversion member 2 with the wavelength conversion member 2 arranged inthe fit-in part 3-2 of the fixed member 1, and performing heating inthis state.

In the optical component shown in FIG. 3, the fixed member 1 and thewavelength conversion member 2 cannot be fixed with a small amount offixing member 6-3 since the cut-in part nor the hole part is formed atthe side surface of the fit-in part 3-2 of the fixed member 1, and thefixing member 6-3 must be arranged around the entire periphery of thewavelength conversion member 2. Thus, the fixed portion of the fixedmember 1 and the wavelength conversion member 2 has a shape in which thelow melting point glass is arranged at the side surface of thewavelength conversion member. In this case, some of the light that exitsfrom the wavelength conversion member 2 is absorbed by the fixing member6-3 and shielded, whereby the light emitting efficiently lowers.

FIG. 4 is a view showing a configuration of a light emitting deviceequipped with the optical component according to the first embodiment ofthe present invention.

The light emitting device shown in FIG. 4 has a mounting platform 7fixed to the through hole 3-1 side arranged opposite the fit-in part3-2, which is fitted with the wavelength conversion member 2, of thefixed member 1 by way of a joining part 9. The fixing method includesweld fixation, fixing agent fixation, and brazing. A light source 8 isarranged on the mounting platform 7, and is arranged at a position wherethe light that exits from the light source 8 is efficiently guided tothe wavelength conversion member.

The attachment of the wavelength conversion member 2 to the fixed member1 is reliably performed with a small amount of fixing member 5-2, andthus none of the fixing member 5-2 goes around to the through hole 3-1side, and properties such as light absorption will not be affected.Therefore, the light that exits from the light source 8 is guided to thewavelength conversion member 2 without being attenuated, and the lightemitting efficiency can be improved. The light source 8 emits lighthaving a light emission peak within the wavelength region of 300 nm to500 nm, and a light emitting diode, a semiconductor laser element etc.is used as the light source.

FIG. 5 is a view showing a configuration of another light emittingdevice equipped with the optical component according to the firstembodiment of the present invention.

The light emitting device shown in FIG. 5 has a light guide holdingmember 11 arranged with a light guide 10 fixed to the through hole 3-1side arranged opposite the fit-in part 3-2, which is fitted with thewavelength conversion member 2, of the fixed member 1 by way of ajoining part 12 arranged on the side surface of the fixed member 1. Thefixing method includes weld fixation and fixing agent fixation.

In weld fixation, the fixed member 1 and the light guide holding member11 can be weld fixed through, e.g. YAG laser welding. In YAG laserwelding, the YAG laser is irradiated onto the fixed member 1 to melt thefixed member 1, thereby weld fixing the fixed member 1 and the lightguide holding member 11. Therefore, the portion weld fixed by the YAGwelding becomes the joining part 12.

In fixing agent fixation, a hole is formed at the side surface of thefixed member 1 in advance, and after the light guide holding member 11is inserted into the through hole 3-1, the fixing material is filledinto the hole formed at the side surface of the fixed member 1, therebyfixing with fixing agent the fixed member 1 and the light guide holdingmember 11. Therefore, the portion fixed by the fixing material becomesthe joining part 12.

The attachment of the wavelength conversion member 2 to the fixed member1 is reliably performed with a small amount of fixing member 5-2, andthus none of the fixing member 5-2 goes around to the through hole 3-1side, and the light guide 10 can be brought closer to the wavelengthconversion member 2. Therefore, the light that exits from the lightguide 10 is guided to the wavelength conversion member 2 without beingattenuated, thereby improving the light emitting efficiency.

The glass used for the wavelength conversion member is preferablysilicate glass. In particular, silicate glass containing one or moretypes of alkali metal oxide, alkali earth metal oxide, boron oxide,phosphorus oxide, zinc oxide is preferable. The wavelength conversionmember is obtained by mixing fluorescent material powder and glasspowder, and performing e.g. heat press molding on the mixed powder.

The fixing material is preferably the low melting point glass having asoftening point at lower than or equal to 650° C.

EXAMPLE

FIG. 6 is a view showing a light emitting device used in evaluating theoptical component according to a first example of the present invention.

In the first example, the transverse cross sectional shape of the fixedmember 1, the through hole 3-1 and the fit-in part 3-2 is circular. Theouter diameter of the fixed member 1 is 1.25 mm, the inner diameter ofthe through hole 3-1 is 0.7 mm, and the inner diameter of the fit-inpart 3-2 is 0.9 mm. The depth of the fit-in part 3-2 is 0.1 mm, and thesize of the cut-in part 5-1 is 0.2 mm in radius and 0.1 mm in depth andis arranged at two locations at opposite angles at the side surface ofthe fit-in part 3-2. The wavelength conversion member 2 also has acolumnar shape having a diameter of 0.9 mm and a thickness of 0.45 mm.The wavelength conversion member 2 is fitted in the fit-in part 3-2, andis fixed by filling the fixing member 5-2 to the cut-in part 5-1. Thematerial of the fixing member 5-2 used for fixing is the low meltingpoint glass having a softening point at 520° C., and is filled by 0.07mg. The light guide holding member 11 arranged with the light guide 10is inserted into the through hole 3-1 of the fixed member 1, and isfixed by a fixing part 13. YAG laser welding is used for fixing.

FIG. 7 shows the output characteristic of the light that exits from thewavelength conversion member 2 when the laser light of about 445 nm isentered from the incident side of the light guide 10. This is comparedwith the optical output characteristic of a sample having a shape inwhich the low melting point glass is arranged on the side surface of thewavelength conversion member as shown in FIG. 3 without using thepresent invention. As a result, the increase by approximately 1.3 timesin light emitting efficiency is achieved by the present invention.

The present invention can be used in light emitting devices such aslight emitting diode and semiconductor laser element.

1. An optical component comprising: a fixed member including a throughhole; and a wavelength conversion member having at least one partthereof arranged in the through hole; wherein said fixed member isformed with a cut-in part or a hole part in a direction substantiallyperpendicular to the longitudinal direction of said through hole.
 2. Theoptical component according to claim 1, wherein said wavelengthconversion member is fixed to said fixed member using a fixing member.3. The optical component according to claim 2, wherein said fixingmember is low melting point glass.
 4. The optical component according toclaim 2, wherein said fixing member is filled into said cut-in part orsaid hole part.
 5. The optical component according to claim 1, whereinsaid fixed member is a tubular body and has an inner hole whosetransverse cross sectional shape is circular shape.
 6. The opticalcomponent according to claim 1, wherein said fixed member includes astep at said through hole.
 7. The optical component according to claim1, wherein a diameter of at least one part of said through hole in saidfixed member is the same as or larger than a diameter of said wavelengthconversion member.
 8. The optical component according to claim 1,wherein said wavelength conversion member is fitted in the through holeof said fixed member.
 9. The optical component according to claim 1,wherein said wavelength conversion member is obtained by mixing afluorescent material in glass.
 10. The optical component according toclaim 9, wherein said glass is silicate glass.
 11. The optical componentaccording to claim 5, wherein said fixed member includes a step at saidthrough hole.
 12. The optical component according to claim 5, wherein adiameter of at least one part of said through hole in said fixed memberis the same as or larger than a diameter of said wavelength conversionmember.
 13. The optical component according to claim 5, wherein saidwavelength conversion member is fitted in the through hole of said fixedmember.
 14. The optical component according to claim 5, wherein saidwavelength conversion member is obtained by mixing a fluorescentmaterial in glass.
 15. The optical component according to claim 14,wherein said glass is silicate glass.